I was friends with this guy once and he was a parliamentary draftsman. That is he drew up the acts of parliament - working with MP's, Governments etc to meet their needs

I once asked him why there was so much uncertainty especially with regard to tax law. "Ah" he said "That is because they are drafted that way" "No one wants us to make laws totally singular - they want them to be interpretable" Why? "Lots more money for accountants and lawyers to advise their clients because the House is full of lawyers and accountants"